The present invention relates to a steering apparatus for a vehicle having a steering wheel and steerable road-engaging wheels.
A known vehicle steering apparatus includes a steering wheel motor which is connectable with a steering wheel of a vehicle. The steering wheel motor is energizable by electric current to resist rotation of the steering wheel. A road wheel steering motor is connectable with steerable road engaging wheels. The road wheel steering motor is energizable by electric current to effect turning movement of steerable road-engaging wheels in response to rotation of the steering wheel.
It has previously been suggested that a variable resistor could be connected in parallel with the steering wheel motor. A steering apparatus having this construction is disclosed in International Patent Application Ser. No. PCT/US01/10566 filed Mar. 30, 2001 disclosing subject matter invented by Daniel E. Williams and assigned to TRW Inc. The aforementioned International Patent Application Ser. No. PCT/US01/10566 claims the benefit of U.S. Provisional Application Ser. No. 60/194,132 filed on Apr. 3, 2000. Another known steering apparatus is disclosed in International Patent Application Ser. No. PCT/US01/40392 filed Mar. 29, 2001 disclosing subject matter invented by William A. Szabela and assigned to TRW Inc. The aforementioned International Patent Application Ser. No. PCT/US01/40392 claims the benefit of U.S. Provisional Applications Ser. Nos. 60/194,134; 60/194,133; and 60/194,129 all filed on Apr. 3, 2000.
The present invention provides a new and improved steering apparatus for a vehicle having a steering wheel and steerable road-engaging wheels. The apparatus includes a steering wheel motor which is connectable with the vehicle steering wheel. The steering wheel motor is energizable by electrical current to resist rotation of the steering wheel. A variable resistor is connected in parallel with the steering wheel motor. The variable resistor is adjustable to vary the electric current which energizes the steering wheel motor.
A road wheel steering motor is connectable with steerable road-engaging wheels of the vehicle. The road wheel steering motor is energizable by electric current to effect turning movement of the steerable road-engaging wheels in response to rotation of the steering wheel. A variable resistor is connected in parallel with the road wheel steering motor. The variable resistor connected in parallel with the road wheel steering motor is adjustable to vary electrical current which energizes the road wheel steering motor.
A variable resistor may be connected in series with the steering wheel motor. Similarly, a variable resistor may be connected in series with the road wheel steering motor. The two resistors which are connected in series with the steering wheel motor and the road wheel steering motor limit electrical current conducted from the respective motors through the variable resistors which are connected in parallel with the motors.